表1 t1id name --------- 1 ning 2 haha 3 loulou表2 t2id age ---------- 1 25 3 23 select t1.id,t1.name,t2.age from t1=t2 where t1.id=t2.id; 结果: id name age ----------------- 1 ning 25 3 loulou 23select t1.id,t1.name,t2.age from t1=t2 where t1.id=t2.id(+); 结果: id name age ----------------- 1 ning 25 2 haha 3 loulou 23
---------
1 ning
2 haha
3 loulou表2 t2id age
----------
1 25
3 23
select t1.id,t1.name,t2.age from t1=t2 where t1.id=t2.id;
结果:
id name age
-----------------
1 ning 25
3 loulou 23select t1.id,t1.name,t2.age from t1=t2 where t1.id=t2.id(+);
结果:
id name age
-----------------
1 ning 25
2 haha
3 loulou 23